To create a VAT only invoice in Procure Wizard the product lines will need to be duplicated i.e. the same product added twice to the order.
To achieve a VAT only value 1 line must be a positive value including the VAT and the second a minus value with zero VAT - this leaves the VAT as the only value shown on the order / invoice.
This can be achieved via:
MP Scan.
Balance Orders.
IP Scan.